Alpen Adria Swim Cup - Klopeiner See

In 1885, the shores of Klopeiner See opened to the public with just 40 guest beds, marking the beginning of a transformation from a quiet agrarian landscape into a specialized health resort. Initially marketed for the restorative climate for those suffering from lung ailments, the lake eventually matured into a summer destination, its history woven into the very hills that now frame the swim course. Today, the water remains the focal point of the Alpen Adria Swim Cup, where the legacy of that early hospitality meets the demands of modern endurance racing.

The Water and the Landscape

As you navigate the course, you are swimming in the remains of a vast post-glacial basin that once extended far beyond the current shoreline. The immediate horizon is dominated by the wooded ridges of the Gracarca and Georgiberg, composed of 'Sattnitz conglomerate'—a soft, tertiary geological deposit that gives the landscape its distinct, undulating profile. On the southeastern shore, the Gracarca hill holds archaeological layers from the Urnfield and Hallstatt cultures, with researchers long theorizing that this high ground may have served as the ancient Celtic capital of Noreia. You are effectively tracing the edges of a site that held significance for regional power long before the first tourists arrived.

Managing the Lake

One of the most defining aspects of this swim is the thermal profile of the water. Fed primarily by groundwater and minor surface streams with very low turnover, the lake consistently reaches surface temperatures among the highest in the Alpine region. This lack of circulation, however, presents an ecological challenge; with a maximum depth of 48 meters and an average of 23, the deeper layers risk oxygen depletion. To address this, a deep-water drainage system has been operational since the 1970s, extracting nutrient-rich water to maintain the clarity and health of the ecosystem you traverse today. During the event, participants should note that while the water is warm, the choice of equipment is a matter of personal strategy rather than environmental necessity, with wetsuits typically being optional depending on the exact conditions of the day.